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Energy Efficient Windows

Windows, redefined.

Energy Efficient Windows & Glazing 

Windows are designed to let in light, while blocking air and objects from entering the house. In addition, windows provide some insulation, but not much. They are only a few millimetres thick, and heat can easily flow through them, making it more expensive to heat and cool your house. Double glazed windows are designed to let light through while blocking the movement of heat, turning your windows into good insulators and are more energy efficient windows.

At Evolution we supply both double and triple glazed energy efficient windows which carry a minimum A+ Rating as standard, which will keep your heating bills low and help conserve the heat produced in your home. Our windows have one of the highest energy ratings and U values in the industry, so your new energy efficient windows will not only be an attractive addition to your home, but a wise investment.

Storm and Flush Windows Energy Ratings

The BSI Energy Rating system is the UK’s national system for rating the energy efficiency of windows and is recognised within the Building Regulations as a method to show compliance. BSI window energy rating uses a traffic-light style A-E ratings guide similar to that used on white goods (such as fridges, freezers, washing machines etc). As well as taking U values into consideration, the BSI energy ratings also take into account the nominal solar heat gain provided by windows.

Window Energy Ratings determine how well a window will perform the functions of helping you contain and conserve heat within your building in the winter. Both A+ rated as standard, the Storm and Flush window ranges take energy efficient windows to the highest level with double glazing to 28mm thickness.

Understanding U Values

U-Values measure how well heat is transferred by the entire energy efficient windows - the frame, sash and glass - either into or out of the building. U Values are measured in W/m2K, the lower the U-Value number, the better the window or door will keep heat inside a building on a cold day.

Both the Storm and Flush window ranges have a 1.3U value and is rated WER A+ as standard. By choosing any windows from the Evolution range you can be assured they will keep your home lovely and warm in winter, cool in the summer and your bills to a minimum, knowing you are not wasting or losing energy.

It has been shown that energy efficient windows will help to minimise heating costs when installed by skilled qualified professionals. Using Evolution will ensure that your windows will be a valuable asset to your home for many years to come.

Triple Glazing - The Ultimate Energy Efficient Windows

To further enhance your homes’ energy saving credentials triple glazed energy efficient windows will ensure that your home is warmer, more secure and will add value to your property. If you live in a noisy area, near an airport, school, or busy road for example, triple glazing will also significantly reduce noise pollution.

Both our Storm and Flush window ranges have the option of upgrading to our ultimate energy rated triple glazing energy efficient windows (with the exception of windows with Georgian bars).

A standard double glazed Storm window has a U value of 1.3 but a triple glazed Storm window has a U value of 1.1. This makes triple glazed windows 15% more energy efficient than double glazed in terms of heat loss, whilst still maintaining the beautiful aesthetics which have become synonymous with the Evolution energy efficient windows collection.

The Finest MaterialsCrafted To Delight

Each of our windows and doors has its own unique journey. At Evolution, we believe there’s no substitute for real craftsmanship. Our time served craftsmen are passionate and highly skilled, with years of experience behind them, honing and developing the method and tools to make our windows the pinnacle of design and technology.









Committed To Quality10 Year Guarantee

Renowned for exceptional service at every stage of the design, manufacture and installation process; our customer care team ensure each customer receives the very best experience. We’re so confident of the enduring quality of the windows and doors we produce, we give a 10 Year guarantee on all Evolution products, providing each customer with the ultimate peace of mind.

Like to know more? Get in Touch

To request your free brochure, free no-obligation quotation, or to request a call back from one of our advisors, please complete your details below. Alternatively call us 01767 821548.


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Your next steps

Request a brochure

If you can’t visit your local Evolution showroom but still want to find out more about our beautiful handcrafted windows and doors then simply order a brochure today and be inspired.


Request a quotation

Speak to one of our friendly, experienced designers to discuss your requirements and individual project needs. We will provide you with advice and a detailed, no-obligation quotation.

Get a quote

Visit a showroom

To truly explore Evolution, why not visit your local showroom where you can see the Evolution difference for yourself. We are also always happy to welcome visitors to our Bedfordshire head office.

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The UK's finest timber alternative windows and doors.